Ground-level ozone pollution is contributing to hundreds of deaths a year in the UK - and climate change could help make the situation worse, a report from the Royal Society warned today.

The study said that background ozone levels had been growing by 6 per cent a decade since the 1980s, and were now at a level where they were having an impact on health and the environment.

The Royal Society publication warned ozone was a significant greenhouse gas, damaged natural ecosystems and reduced the yields and quality of crops such as wheat and rice.

According to the Royal Society, 1,582 deaths in the UK in 2003 were attributed to ozone's effects on people's respiratory systems, while across Europe some 21,400 deaths a year are caused by the gas.

The Ground Level Ozone in the 21st Century report said the UK figure looked set to increase by at least 50 per cent by 2020 as a result of growing emissions and climate change.

Policies in the EU, the US and Japan have successfully reduced peak regional concentrations of the pollutant, which is formed by reactions between other gases - including greenhouse gases methane and nitrogen oxides - in the presence of sunlight.